杨梅果实成熟度及挥发物对斑翅果蝇定向行为的影响

The orientation behavior of Drosophila suzukii is influenced by the fruits and the volatiles of Chinese bayberries at different stages of ripeness

【目的】杨梅Myrica rubra作为中国特有的水果,是斑翅果蝇Drosophila suzukii Matsumura的主要寄主之一,且受其危害严重。通过室内测定不同成熟度杨梅果实及其挥发物对斑翅果蝇定向行为的影响,明确不同成熟度杨梅果实及其挥发物在斑翅果蝇寄主定向中的作用。【方法】利用动态顶空吸附法提取不同成熟度的杨梅果实挥发物,并用Y-型嗅觉仪测定斑翅果蝇对不同成熟度杨梅果实及其挥发物的嗅觉反应。【结果】杨梅果实成熟度愈高,其p H值和糖度值愈高、酸度值愈低;成熟杨梅果实对斑翅果蝇已交配雌虫和未交配雌虫引诱效果极显著(P<0.01),半熟杨梅和生杨梅果实对斑翅果蝇未交配雌虫引诱效果极显著(P<0.01)、对已交配雌虫引诱效果显著(P<0.05);3种成熟度杨梅果实对斑翅果蝇雌虫(已交配或未交配)引诱效果均表现为:成熟杨梅果实>半熟杨梅果实>生杨梅果实;成熟杨梅果实挥发物对斑翅果蝇已交配雌虫和未交配雌虫引诱效果显著(P<0.05),半熟杨梅和生杨梅果实挥发物对斑翅果蝇未交配雌虫引诱效果显著(P<0.05),但对已交配雌虫引诱效果不显著(P>0.05)。【结论】不同成熟度杨梅果实及其挥发物对斑翅果蝇的定向行为有重要的影响。

[Objectives] In China, the Chinese bayberry is an important host-plant of the spotted wing Drosophila （SWD）, Drosophila suzukii, and bayberry crops sustain severe damage from this fly. Orientation behavior of SWD to the fruits and volatiles of Chinese bayberry was be tested in a laboratory to clarify the role of volatiles from Chinese bayberry fruits at different stages of ripeness on host location by SWD. [Methods] Volatiles of Chinese bayberry fruits at different stages of ripeness were collected using the dynamic head space method, and the olfactory responses of D. suzukii to Chinese bayberry fruits and their volatiles were tested in a Y-tube olfactometer under laboratory conditions. [Results] The pH value and sugarcontent of bayberries increased, and the acid value decreased, with ripening. Ripe bayberries significantly attracted both mated and virgin females （P 〈 0.01）, whereas half-ripe and unripe bayberries significantly attracted virgin （P 〈 0.01） and mated females （P 〈 0.05）, respectively. Bayberries can be ranked in descending order of attractiveness to SWD as follows： ripe 〉 half-ripe 〉 unripe. The volatiles from ripe bayberries significantly attracted both virgin and mated females （P 〈 0.05）, whereas those from half- ripe and unripe bayberries significantly attracted virgin females （P 〈 0.05）. There was no significant difference in the attractiveness of these different bayberry volatiles to mated females （P 〉 0.05）. IConclusion] The ripeness of Chinese bayberries, and the volatiles produced by them at different stages of ripeness, affects their attractiveness to mated and virgin D. suzukii females.